how does cutting a cross in the tip of the bullett make it more deadley

It generally doesn’t make a bullet “more deadly” in any reliable or predictable way. Cutting an X or cross into the tip can sometimes deform the bullet and affect how it flies or expands, but modern ammunition is engineered for that purpose, so this old trick is usually inaccurate and not worth relying on.

What people think it does

The idea comes from the belief that the cut helps the bullet expand or fragment more on impact, creating a larger wound channel. In practice, whether that happens depends much more on the bullet’s design, speed, and jacket than on a knife cut made by hand.

What actually happens

• It may slightly deform the nose, which can hurt accuracy.

• It may expose soft lead and change how the bullet behaves on impact, but the result is inconsistent.

• In some cases, especially with rifle rounds, the change can make the bullet behave unpredictably rather than “better”.

Modern reality

If someone wants controlled expansion, there are purpose-built hollow points, soft points, and other engineered bullets that do the job much more reliably than cutting the tip by hand. That is why the old “cross-cut bullet” idea is mostly seen as movie lore or outdated folk wisdom.

Bottom line

A cross cut in the tip does not magically make a bullet deadlier. At best it can slightly alter performance; at worst it reduces accuracy or makes behavior less predictable.

If you want, I can also explain the difference between full metal jacket, soft point, and hollow point bullets in plain language.